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Paint shine

Posted: Sun Dec 15, 2013 6:24 pm
by stag36587
Hello

I'd welcome opinions on this paintwork - it's had a couple
cellulose top coats so far but I've not yet used any rubbing compound or polish.

My question is whether the paint should be shinier than this at this stage (i.e. before polishing)? It seems a bit flat to me. I'm planning to use 1000 grit wet/dry over whole car then rubbing compound followed by polish. Does that sound right approach or do you think I need a further wetter paint coat first?

Thanks for all views[frame]Image[/frame]

Re: Paint shine

Posted: Sun Dec 15, 2013 6:58 pm
by les
Was It damp outside when you sprayed it, they used to make anti bloom thinners to help with this problem. You need a decent day or well heated workshop to get a shine from the gun.

Re: Paint shine

Posted: Sun Dec 15, 2013 7:05 pm
by stag36587
Hi Les I think you were looking at my pre-restoration sig photo. The main pic
was too big to upload but now sorted.

Re: Paint shine

Posted: Sun Dec 15, 2013 7:06 pm
by lambrettalad
if the paint work has a milky sheen then its bloomed,if not try mixing 25% t-cut to 75% good quality polish and try out in a safe area,see if it shines and stays that way,To be have a real deep shine put at least 5 coats ,flat it then apply two more coats then polish ,good luck :D

Re: Paint shine

Posted: Mon Dec 16, 2013 6:40 am
by Redmoggy
Cut the finish with 1200 wet and dry. Then mix up a 50/50 mix of celly and a 2K thinner. Finish with two or three slow coats mixed 25/75, paint to thinner. The 2K thinner takes longer to flash off than standard Celly thinner, consequently giving you a better finish.

Rod

Re: Paint shine

Posted: Mon Dec 16, 2013 7:26 am
by kennatt
yes use 2k if you want to risk killing yourself,and everybody else in the area,unless you have a full air fed mask,and a commercial grade filter on the garage :o . All 2k products contain isocyanate don't go near it.
.Its hard to get a shine from the gun with celly unless the conditions are perfect,heat, humidity ,paint quality and expert application. But its good for DIY because it is easy to rectify faults afterwards,sags and bits of grit etc.As long as you have put four or five top coats on,as a minimum,wet flatting with 1200 grit,followed by a good cutting compound and then a good quality polish will give you a good shine,just takes a bit of time panel by panel.Just be careful on sharp edges that you don't cut through to the primer.
When I served my time as a coach builder paint sprayer the celly used to need just a quick buffing afterwards,but that was 40 years ago,and like everything else the quality of the products were far better than the rubbish you can get these days. I think even the pro shops that use celly need to do considerable polishing,Thats why they all use 2k or waterbased with 2k lacquer on top.But they have ovens to bake the car ,home spraying dosen't have that facility. Get the elbow grease out you'll get there :D :D

Re: Paint shine

Posted: Mon Dec 16, 2013 8:09 am
by Redmoggy
I am happy to be proved wrong, but none of the data sheets i have found list isocianates in 2K thinner, only the paint. This is my old Morrie painted in celly with a slow 2K thinner. It's gun finished and not buffed.[frame]Image[/frame]

Re: Paint shine

Posted: Mon Dec 16, 2013 8:12 am
by irmscher
Looks like you got a nice finish on the red one :D

Re: Paint shine

Posted: Mon Dec 16, 2013 11:00 am
by stag36587
Really helpful advice guys, many thanks!

Re: Paint shine

Posted: Mon Dec 16, 2013 12:12 pm
by lambrettalad
Preparation is king ,with paint work

Re: Paint shine

Posted: Mon Dec 16, 2013 12:37 pm
by kennatt
yes redmoggie,I think you are probably right,thinking about it,the iso is in the hardner. The only thing is the length of time for the paint to flash off,would need a dust free area,its not so much of a problem with celly only. did you have a heater or just in normal garage,how long before it flashed off.
I may look into this, need to spray a nose cone on another project,may try it,still think there will be a problem with sinkage when the previous coat is still soft,but suppose if you do the first few coats in celly only then, when dry flat down, and top coat with your system,hmmm worth a try.

Re: Paint shine

Posted: Tue Dec 17, 2013 7:08 am
by Redmoggy
Kennatt. Dont take it to literally. The slower thinner does not turn it into the old synthetics that stayed sticky for days. Think off it like this. As you apply your final wet coats, you slow down and overlap each smooth shiney coat. This is when the slower thinner comes into it's own. By taking just a little longer to evaporate you can avoid laying down dry coats and have a gun finish shine. I allowed 10-15 mins between coats and just kept thinning until i ran out of paint. No need for any extra precausions or a heater (assuming you pick a good day). Shrinkage also should not be a problem.

Try it, you might like it!
Rod

Re: Paint shine

Posted: Tue Dec 17, 2013 9:58 am
by Neil MG
Difficult to be able to say without seeing the paint. It is not clear from the picture whether the paint has bloomed or whether it is just sprayed too dry. That is quite normal if you haven't done a lot of spraying and want to avoid runs, but may actually not be that easy to fix. If you only put two fairly dry coats on it will be difficult to flat and polish without rubbing through. Cellulose does not have such a high film thickness, which is why multiple coats are applied. Like Rod says it is normal to finish with more thinners in the final coats. I have heard of people spraying a final coat of just thinners, but never seen it.

Regarding flatting and polishing I would recommend block sanding with 1500 and a machine polisher if you want a really nice shine. 1000 and rubbing compound by hand would take days and even then, not give the best result. As with all things, try a small easily repaired or less conspicuous panel first to see how much work is involved and check it in good daylight, preferably sunlight to see how it will look.

My personal opinion would be to leave it until Spring (to fully harden) then block sand with 800 before applying another few coats of paint and going for a better finish out of the gun before cutting and polishing.

Re: Paint shine

Posted: Tue Dec 17, 2013 2:11 pm
by irmscher
What machine polisher is best rpm etc

Re: Paint shine

Posted: Tue Dec 17, 2013 9:55 pm
by Morris Mike
Two of these are finished in two pack paint,the third is finished in cellulose.
The spraying technique is totally different when spraying the different paint products.

Cellulose by nature of its solvents is a more air born product,that is why you can hardly see when spraying in your garage or workshop,unless you have extraction equipment.
The coats when laid on are thin,that is why you have to put say 5/6 coats,leave overnight,wet flat with 1200,then lay on another 5 coats.
Leave to harden for a few days,if you have laid the paint on properly with a good clean finish wet sand with 2000,if the finish is very heavy looking wet sand with 1200 then 2000.

Cut back the paintwork with Farecla G3/G4. Finish off with G10. Then apply a good wax polish to seal the paint...i.e Autoglym.
Machine polish for ease or do it by hand.

In the 1980`s I used a paint product called Gypfast 60 cellulose. I would display a vehicle at one of the indoor events under bright lights,everyone thought the vehicles were finished in 2 pack paint because the finish was that good.
Only hard work preparing and then applying the paint made the finish so good.

Another trick to get that perfect paint finish so that it looked like glass was to finally cut the paint back with Brasso.
Very time consuming but worth it in the end.

We would polish our vehicles so much before a show our arms ached that much we could not lift a pint of ...Double Diamond. Although the advert said it "Worked Wonders."

M.M

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Re: Paint shine

Posted: Thu Dec 19, 2013 5:35 pm
by tysonn
Machine polisher has variable speed Lee.

Re: Paint shine

Posted: Mon Dec 23, 2013 6:02 am
by GBond
I've been doing like Mike said to my car but following the 2000 grit sanding with 3000 and then 5000 before the rubbing compound. The results are astonishing but it does take quite some time. I'll post some pictures up when I'm done.

Re: Paint shine

Posted: Mon Dec 23, 2013 9:41 pm
by stag36587
GBond wrote:I've been doing like Mike said to my car but following the 2000 grit sanding with 3000 and then 5000 before the rubbing compound. The results are astonishing but it does take quite some time. I'll post some pictures up when I'm done.
I'll look forward to seeing your pictures, thanks

Re: Paint shine

Posted: Wed Dec 25, 2013 1:11 am
by irmscher
Wish I could paint like that :( solve all my problems

Re: Paint shine

Posted: Wed Dec 25, 2013 8:12 pm
by Morris Mike
3000 then 5000 sounds a bit over the top.?

You mentioned in your first post that you had only put on two coats of cellulose paint. That is not really enough.

You really ought to have flatted down the existing paint with 1200,then applied at least four more coats of cellulose.
This way you would have had some body of paint to start flatting and polishing.

M.M